December 1999 arXiv papers — page 2
Showing 101–200 of 2,544 papers
Angel Morales
The status of the recent efforts in the direct search for Weak Interacting Massive Particle (WIMP) Dark Matter is briefly reviewed and the main achievements illustrated by the contributions presented to TAUP 99. The strategies followed in the quest for WIMPs will be first revisited and then the new results and the future prospects reported.
Brajesh Kumar, R. Jain, S. C. Tripathy, Hari Om Vats
A time series of GONG Dopplergrams for the period 10-14 May 1997 from Udaipur and Big Bear sites has been used to measure the velocity fluctuations in the sunspot (NOAA active region 8038) and quiet photosphere simultaneously. We observe that the power of pre-dominant p-mode is reduced in the sunspot as compared to quiet photosphere by 39-52% depending on th
S. B. Popov, M. E. Prokhorov, V. M. Lipunov
This paper is a continuation and development of our previous articles (Popov et al., 1997, 1998). We use `Scenario Machine'' (Lipunov et al., 1996b) -- the population synthesis simulator (for single binary systems calculations the program is available in WWW: http://xray.sai.msu.ru/ (Nazin et al., 1998)) -- to calculate evolution of populations of se
S. B. Popov
I discuss the nature of the compact X-ray source in the center of the supernova remnant RCW 103. Several models, based on the accretion onto a compact object are analyzed. I show that it is more likely that the central X-ray source is an accreting neutron star than an accreting black hole. I also argue that models of a disrupted binary system consisting of a
V. Burdyuzha, Ph. Durouchoux, V. Kauts
The possibility of positronium detection at radio wavelengths is investigated in detail. For orthopositronium, the fine structure lines of the n = 2 level (1.62 cm, 2.30 cm and 3.48 cm) may be probably detected by radiotelescopes of next generations with the sensitivity around 1 microJansky. The spin-flip line of the ground state (0.147 cm) may be observed f
Eva K. Grebel
In about 40% of the Local Group galaxies star clusters have been detected so far, but the census is still incomplete. The properties of these clusters are briefly reviewed, and the impact of galaxy environment on the evolution and survival of star clusters is discussed. Several (but not all) Local Group galaxies seem to share a common epoch of the earliest g
Yoshiaki Mizuno, Takami Tohyama, Sadamichi Maekawa
The magnetic interactions in one-dimensional, two-dimensional (2D) and ladder cuprates are evaluated systematically by using small Cu-O clusters. We find that the superexchange interaction J between nearest neighbor Cu spins strongly depends on Cu-O structure through the Madelung potential, and in 2D and ladder cuprates there is a four-spin interaction Jcyc,
Kazutoshi Ohta, Takashi Yokono
We study the relation between intersecting NS5-branes whose intersection is smoothed out and the deformed conifold in terms of the supergravity solution. We solve the condition of preserved supersymmetry on a metric inspired by the deformed conifold metric and obtain a solution of the NS5-branes which is delocalized except for one of the overall transverse d
Jeremiah P. Ostriker
If the cosmological dark matter is primarily in the form of an elementary particle which has cross section and mass for self-interaction having a ratio similar to that of ordinary nuclear matter, then seed black holes (formed in stellar collapse) will grow in a Hubble time, due to accretion of the dark matter, to a mass range 10^6 - 10^9 solar masses. Furthe
Wigner Crystal State for the Edge Electrons in the Quantum Hall Effect at Filling $ν= 2$
cond-mat.mes-hallJ. P. Rodriguez, M. J. Franco, L. Brey
The electronic excitations at the edges of a Hall bar not much wider than a few magnetic lengths are studied theoretically at filling $ν= 2$. Both mean-field theory and Luttinger liquid theory techniques are employed for the case of a null Zeeman energy splitting. The first calculation yields a stable spin-density wave state along the bar, while the second o
Luiz C. de Albuquerque, Nelson A. Alves, D. Dalmazi
We obtain in a closed form the 1/N^2 contribution to the free energy of the two Hermitian N\times N random matrix model with non symmetric quartic potential. From this result, we calculate numerically the Yang-Lee zeros of the 2D Ising model on dynamical random graphs with the topology of a torus up to n=16 vertices. They are found to be located on the unit
T. R. Kirkpatrick, D. Belitz
The theory for disordered itinerant ferromagnets developed in a previous paper is used to construct a simple effective field theory that is capable of describing the quantum phase transition from a ferromagnetic metal to a ferromagnetic insulator. It is shown that this transition is in the same universality class as the one from a paramagnetic metal to a par
T. R. Kirkpatrick, D. Belitz
A comprehensive theory for electronic transport in itinerant ferromagnets is developed. We first show that the Q-field theory used previously to describe a disordered Fermi liquid also has a saddle-point solution that describes a ferromagnet in a disordered Stoner approximation. We calculate transport coefficients and thermodynamic susceptibilities by expand
Dmitri Diakonov, Victor Petrov
We perform the dual transformation of the Yang-Mills theory in d=3 dimensions using the Wilson action on the cubic lattice. The dual lattice is made of tetrahedra triangulating a 3-dimensional curved manifold but embedded into a flat 6-dimensional space (for the SU(2) gauge group). In the continuum limit the theory can be reformulated in terms of 6-component
O. Bertolami, C. S. Carvalho
Working in the context of a Lorentz-violating extension of the standard model we show that estimates of Lorentz symmetry violation extracted from ultra-high energy cosmic rays beyond the Greisen-Kuzmin-Zatsepin (GZK) cutoff allow for setting bounds on parameters of that extension. Furthermore, we argue that a correlated measurement of the difference in the a
L. Feher, B. G. Pusztai
The most general momentum independent dynamical r-matrices are described for the standard Lax representation of the degenerate Calogero-Moser models based on $gl_n$ and those r-matrices whose dynamical dependence can be gauged away are selected. In the rational case, a non-dynamical r-matrix resulting from gauge transformation is given explicitly as an antis
Shao-shiung Lin, Shi-shyr Roan
We study the diagonalization problem of certain Hofstadter-type models through the algebraic Bethe ansatz equation by the algebraic geometry method. When the spectral variables lie on a rational curve, we obtain the complete and explicit solutions for models with the rational magnetic flux, and discuss the Bethe equation of their thermodynamic flux limit. Th
Deog Ki Hong, Taekoon Lee, Dong-Pil Min
We reexamine the quark mass induced term in chiral Lagrangian in color-flavor locking phase in dense QCD, and show that the meson mass term is determined by three independent invariants under chiral-axial symmetry, and a meson mass is given in terms of the quark mass, gap, and the chemical potential by $m_π^2\sim m_q^2Δ\barΔ/μ^2\ln(μ^2/Δ^2)$. Thus mesons bec
Yoshio Kikukawa
We discuss locality in the domain-wall QCD through the effective four-dimensional Dirac operator which is defined by the transfer matrix of the five-dimensional Wilson fermion. We first derive an integral representation for the effective operator, using the inverse five-dimensional Wilson-Dirac operator with the anti-periodic boundary condition in the fifth
Kashif Alvi
An approximate solution to Einstein's equations representing two widely-separated non-rotating black holes in a circular orbit is constructed by matching a post-Newtonian metric to two perturbed Schwarzschild metrics. The spacetime metric is presented in a single coordinate system valid up to the apparent horizons of the black holes. This metric could be
Jen-Hsu Chang, Ming-Hsien Tu
We investigate the Miura map between the dispersionless KP and dispersionless modified KP hierarchies. We show that the Miura map is canonical with respect to their bi-Hamiltonian structures. Moreover, inspired by the works of Takasaki and Takebe, the twistor construction of solution structure for the dispersionless modified KP hierarchy is given.
E. Allahyarov, H. Loewen
The effective interaction between two parallel strands of helical bio-molecules, such as deoxyribose nucleic acids (DNA), is calculated using computer simulations of the "primitive" model of electrolytes. In particular we study a simple model for B-DNA incorporating explicitly its charge pattern as a double-helix structure. The effective force and th
Robert D. Pisarski
Based upon the analogy to the electroweak phase diagram, I propose that in QCD there might be a critical line for a superfluid transition, in the plane of chemical potential and temperature. The order parameter has the quantum numbers of the H-dibaryon, but the transition is driven by color superconductivity in strange quark matter.
Di Qing, He-ming Sun, Fan Wang
$d^*$ dibaryon study is a critical test of hadron interaction models. The electro production cross sections of $ed\to ed^*$ have been calculated based on the meson exchange current model and the cross section around 30 degree of 1 GeV electron in the laboratory frame is about 10 nb. The implication of this result for the $d^*$ dibaryon search has been discus
Michelle M. Wyss, Walter Wyss
The evolution of a quantity, described by a function of space and time, relates the first derivative in time of this function to a spatial operator applied to the function. The initial value of the function at time $t=0$ is given. The fractional extension of this evolution consists of replacing the first derivative in time by a fractional derivative of order
Walter Wyss
Within the Lagrange formalism we show that the gauge invariant total energy-momentum tensor for gravitational interactions is zero. If the equations of motion are satisfied the energy tensor is conserved.
Dmitri Nikshych
We prove a duality theorem for quantum groupoid (weak Hopf algebra) actions that extends the well-known result for usual Hopf algebras.
David Bruce Wilson
In this article we describe a new coupling technique which is useful in a variety of perfect sampling algorithms. A multishift coupler generates a random function f() so that for each real x, f(x)-x is governed by the same fixed probability distribution, such as a normal distribution. We develop the class of layered multishift couplers, which are simple and
Dimitri Shlyakhtenko
We define an analog of Voiculescu's free entropy for n-tuples of unitaries (u_{1},...,u_{n}) in a tracial von Neumann algebra M, normalizing a unital diffuse abelian subalgebra B in M. Using this quantity, we define the free dimension δ_{0}(u_{1},..,u_{n}\btw B). This number depends on (u_{1},... ,u_{n}) only up ``orbit equivalence'' over B. In p
Kefeng Liu, Weiping Zhang
We use adiabatic limits to study foliated manifolds. The Bott connection naturally shows up as the adiabatic limit of Levi-Civita connections. As an application, we then construct certain natural elliptic operators associated to the foliation and present a direct geometric proof of a vanshing theorem of Connes[Co], which extends the Lichnerowicz vanishing th
Vadim E. Levit, Eugen Mandrescu
A maximum stable set in a graph G is a stable set of maximum cardinality. S is a local maximum stable set if it is a maximum stable set of the subgraph of G spanned by the union of S and N(S), where N(S) is the neighborhood of S. One theorem of Nemhauser and Trotter Jr., working as a useful sufficient local optimality condition for the weighted maximum stabl
Mark Hovey
In this paper, we classify certain subcategories of modules over a ring R. A wide subcategory of R-modules is an Abelian subcategory of R-Mod that is closed under extensions. We give a complete classification of wide subcategories of finitely presented modules when R is a quotient of a regular commutative coherent ring by a finitely generated ideal. This inc
Factorization theorem for the transfer function of a 2x2 operator matrix with unbounded couplings
math.SPV. Hardt, R. Mennicken, A. K. Motovilov
We consider the analytic continuation of the transfer function associated with a 2x2 operator matrix having unbounded couplings into unphysical sheets of its Riemann surface. We construct a family of non-selfadjoint operators which factorize the transfer function and reproduce certain parts of its spectrum including the nonreal (resonance) spectrum situated
Regularized derivatives in a 2-dimensional model of self-interacting fields with singular data
math.APGuenther Hoermann, Michael Kunzinger
The coupled Maxwell-Lorentz system describes feed-back action of electromagnetic fields in classical electrodynamics. When applied to point-charge sources (viewed as limiting cases of charged fluids) the resulting nonlinear weakly hyperbolic system lies beyond the scope of classical distribution theory. Using regularized derivatives in the framework of Colom
Eric D'Hoker, D. H. Phong
We present a series of four self-contained lectures on the following topics: (I) An introduction to 4-dimensional 1\leq N \leq 4 supersymmetric Yang-Mills theory, including particle and field contents, N=1 and N=2 superfield methods and the construction of general invariant Lagrangians; (II) A review of holomorphicity and duality in N=2 super-Yang-Mills, of
D. Dalmazi, A. de Souza Dutra, Marcelo Hott
We calculate the effective action for Quantum Electrodynamics (QED) in D=2,3 dimensions at the quadratic approximation in the gauge fields. We analyse the analytic structure of the corresponding nonlocal boson propagators nonperturbatively in k/m. In two dimensions for any nonzero fermion mass, we end up with one massless pole for the gauge boson . We also c
J. Ambjorn, J. Correia, C. Kristjansen, R. Loll
Starting from 2D Euclidean quantum gravity, we show that one recovers 2D Lorentzian quantum gravity by removing all baby universes. Using a peeling procedure to decompose the discrete, triangulated geometries along a one-dimensional path, we explicitly associate with each Euclidean space-time a (generalized) Lorentzian space-time. This motivates a map betwee
Satoru Saito, Kazunori Wakatsuki
We propose a new star pruduct which interpolates the Berezin and Moyal quantization. A multiple of this product is shown to reduce to a path-integral quantization in the continuous time limit. In flat space the action becomes the one of free bosonic strings. Relation to Kontsevich prescription is also discussed.
U. K. Yang, A. Bodek
M. Melnitchouk et al. [hep-ex/9912001] misunderstand the model of Frankfurt and Strikman for nuclear binding effects in deep inelastic scattering (DIS). In addition, their comment is entirely irrelevant to the results of our article.
Robert Bluhm, Alan Kostelecky
Experiments using macroscopic samples of spin-polarized matter offer exceptional sensitivity to Lorentz and CPT violation in the electron sector. Data from existing experiments with a spin-polarized torsion pendulum provide sensitivity in this sector rivaling that of all other existing experiments and could reveal spontaneous violation of Lorentz symmetry at
R. D. Peccei
After discussing alternative scenarios for the origins of the electroweak symmetry breaking, I briefly review the experimental status of the Standard Model. I explore further both the hints for, and constraints on, supposing that that a supersymmetric extension of the Standard Model exists, with supersymmetry broken at the weak scale. I end with a few commen
Per Osland, Tai Tsun Wu
Under the assumption that the density variation of the electrons can be approximated by an exponential function, the solar Mikheyev-Smirnov-Wolfenstein effect is treated for three generations of neutrinos. The generalized hypergeometric functions that result from the exact solution of this problem are studied in detail, and a method for their numerical evalu
A. Edin, G. Ingelman, J. Rathsman
The models for soft colour interactions and colour string re-interactions, implemented in the Monte Carlo program LEPTO, are investigated regarding hadronic final states in inclusive and diffractive deep inelastic scattering.
A. Edin, G. Ingelman, K. Torokoff
A model for the parton distributions in hadrons is derived from simple physical arguments leading to an analytical expression for the valence distributions. The sea parton distributions arise mainly from pions in hadronic fluctuations. Evolving from a low Q^2_0 scale with DGLAP gives the proton structure function F_2(x,Q^2) in good agreement with DIS data. A
G. Ingelman, A. Edin, R. Enberg, J. Rathsman
Improved understanding of non-perturbative QCD dynamics can be obtained in terms of soft colour exchange models. Their essence is the variation of colour string-field topologies giving a unified description of final states in high energy interactions. In particular, both events with and without large rapidity gaps are obtained in agreement with data from ep
A. Edin, G. Ingelman
The non-perturbative parton distributions in hadrons are derived from simple physical arguments resulting in an analytical expression for the valence parton distributions. The sea partons arise mainly from pions in hadronic fluctuations. The model gives new insights and a good description of structure function data.
G. Ingelman, A. Edin, R. Enberg, J. Rathsman
Diffractive deep inelastic scattering at HERA and diffractive W and jet production at the Tevatron are well described by soft colour exchange models. Their essence is the variation of colour string-field topologies giving both gap and no-gap events, with a smooth transition and thereby a unified description of all final states.
Gunnar Ingelman
Diffraction is an old subject which has received much interest in recent years due to the advent of diffractive hard scattering. We discuss some theoretical models and experimental results that have shown new striking effects, e.g. rapidity gaps in jet and W production and in deep inelastic scattering. Many aspects can be described through the exchange of a
Luis Bento
Quantum Field Theory is applied to study an electron plasma under an intense neutrino flux. The dispersion relation of the longitudinal waves is derived and the damping rate is calculated. It is shown that in the case of Supernova emission the neutrinos are not collimated enough to cause plasma instabilities associated to a strong neutrino resonance effect.
Kh. M. Beshtoev
In this paper, we study a photon, a massive charged particle, and a massive neutrino passing through matter. The hypothetical left-right symmetric weak interaction, which is used in Wolfenstein's equation can generate the resonance enhancement of neutrino oscillations in matter, which disappears when neutrinos go out into vacuum from matter (the Sun). It
S. Carlip
String theory and ``quantum geometry'' have recently offered independent statistical mechanical explanations of black hole thermodynamics. But these successes raise a new problem: why should models with such different microscopic degrees of freedom yield identical results? I propose that the asymptotic behavior of the density of states at a black hol
Irina Dymnikova
We propose to describe the dynamics of a cosmological term in the spherically symmetric case by an r-dependent second rank symmetric tensor invariant under boosts in the radial direction. This proposal is based on the Petrov classification scheme and Einstein field equations in the spherically symmetric case. The inflationary equation of state p=-ρis satisfi
Dongsu Bak, Sang Pyo Kim, Sung Ku Kim, Kwang-Sup Soh
We study the analytic structure of the S-matrix which is obtained from the reduced Wheeler-DeWitt wave function describing spherically symmetric gravitational collapse of massless scalar fields. The simple poles in the S-matrix occur in the Euclidean spacetime, and the Euclidean Wheeler-DeWitt equation is a variant of the Calogero models, which is discussed
Sang Pyo Kim
We investigate the thermodynamic arrow of time in a time-symmetrically recollapsing universe by calculating quantum mechanically the entropy production of a massive scalar field. It is found that even though the Hamiltonian has a time-reversal symmetry with respect to the maximum expansion of the universe, the entropy production is generic and the total entr
A. V. Toporensky
The dynamics of closed scalar field FRW cosmological models is studied for several types of exponentially and more than exponentially steep potentials. The parameters of scalar field potentials which allow a chaotic behaviour are found from numerical investigations. It is argued that analytical studies of equation of motion at the Euclidean boundary can prov
Gap to Transition Temperature Ratio in Density Wave Ordering: a Dynamical Mean Field Study
cond-mat.str-elS. Blawid, A. J. Millis
We use the dynamical mean-field method to determine the origin of the large ratio of the zero temperature gap to the transition temperature observed in most charge density wave materials. The method is useful because it allows an exact treatment of thermal fluctuations. We establish the relation of the dynamical mean-field results to conventional diagrammati
Ranjini Bandyopadhyay, Geetha Basappa, A. K. Sood
The nonlinear flow behaviour of a viscoelastic gel formed due to entangled, cylindrical micelles in aqueous solutions of the surfactant CTAT has been studied. On subjecting the system to a step shear rate lying above a certain value, the shear and normal stresses show interesting time dependent behaviour. The analysis of the measured time series shows the ex
Electron renormalization of sound interaction with two-level systems in superconducting metglasses
cond-matE. V. Bezuglyi, A. L. Gaiduk, V. D. Fil, S. V. Zherlitsyn
The crossing of temperature dependencies of sound velocity in the normal and the superconducting state of metallic glasses indicates renormalization of the intensity of sound interaction with two-level systems (TLS) caused by their coupling with electrons. In this paper we have analyzed different approaches to a quantitative description of renormalization us
Sang Pyo Kim
We apply the Liouville-von Neumann (LvN) approach to open systems to describe the nonequilibrium quantum evolution. The Liouville-von Neumann approach is a unified method that can be applied to both time-independent (closed) and time-dependent (open) systems and to both equilibrium and nonequilibrium systems. We study the nonequilibrium quantum evolution of
Sumio Ishihara, Sadamichi Maekawa
A theory of resonant x-ray scattering in perovskite manganites is developed by applying the group theory to the correlation functions of the pseudospin operators for the orbital degree of freedom. It is shown that static and dynamical informations of the orbital state are directly obtained from the elastic, diffuse and inelastic scatterings due to the tensor
Takeya Tsurumi, Hirofumi Morise, Miki Wadati
Bose-Einstein condensation has been realized in dilute atomic vapors. This achievement has generated immerse interest in this field. Presented is a review of recent theoretical research into the properties of trapped dilute-gas Bose-Einstein condensates. Among them, stability of Bose-Einstein condensates confined in traps is mainly discussed. Static properti
Competition between ferromagnetic and charge-orbital ordered phases in Pr$_{1-x}$Ca$_{x}$MnO$_3$ for $x$=1/4, 3/8, and 1/2
cond-mat.str-elTakashi Hotta, Elbio Dagotto
Spin, charge, and orbital structures in models for doped manganites are studied by a combination of analytic mean-field and numerical relaxation techniques. At realistic values for the electron-phonon and antiferromagnetic $t_{2g}$ spin couplings, a competition between a ferromagnetic (FM) phase and a charge-orbital ordered (COO) insulating state is found fo
Craig J. Hogan
The Cold Dark Matter paradigm successfully explains many phenomena on scales larger than galaxies, but seems to predict galaxy halos which are more centrally concentrated and have a lumpier substructure than observed. Endowing cosmic dark matter with a small primordial velocity dispersion preserves the successful predictions of the Cold Dark Matter scenario
Richard Mushotzky
I review the evidence from clusters and groups of galaxies for `relic' evidence of the high redshift universe. Contrary to the received wisdom, clusters are old. Their x-ray emitting intergalactic medium in massive clusters is a reservoir of metal and energy injection from the main epoch of star formation. There are strong indications that non-gravitatio
P. Meszaros
The successful discovery of X-ray, optical and radio afterglows of GRB has made possible the identification of host galaxies at cosmological distances. The energy release inferred in these outbursts place them among the most energetic and violent events in the Universe. They are thought to be the outcome of a cataclysmic stellar collapse or compact stellar m
S. B. Popov, V. M. Lipunov
Estimates of the magnetic field of neutron stars in X-ray pulsars are obtained using the hypothesis of the equilibrium period for disk and wind accretion and also from the BATSE data on timing of X-ray pulsars using the observed maximum spin-down rate. Cyclotron lines at energies $\ge 100$ keV in several Be-transient are predicted for future observations. We
A. De Luca, R. P. Mignani, P. A. Caraveo
Using all the HST WFC/WFPC2 images of the field collected so far, we have performed an accurate relative astrometry analysis to re-assess the value of the Vela pulsar proper motion. Although covering a much shorter time span, our measurement clearly confirms the previous result obtained by Nasuti et al. (1997) using ground-based optical data and nails the pr
Vladimir Burdyuzha, Olga Lalakulich, Yuri Ponomarev, Grigory Vereshkov
The problem of the physical nature and the cosmological constant genesis is discussed. This problem can't be solved in terms of the current quantum field theory which operates with Higgs and nonperturbative vacuum condensates and takes into account the changes of these condensates during relativistic phase transitions. The problem can't be completely
Nadav M. Shnerb, Yoram Louzoun, Eldad Bettelheim, Sorin Solomon
Many systems in chemistry, biology, finance and social sciences present emerging features which are not easy to guess from the elementary interactions of their microscopic individual components. In the past, the macroscopic behavior of such systems was modeled by assuming that the collective dynamics of microscopic components can be effectively described col
Paul Bode, Jeremiah P. Ostriker, Guohong Xu
The Tree-Particle-Mesh (TPM) N-body algorithm couples the tree algorithm for directly computing forces on particles in an hierarchical grouping scheme with the extremely efficient mesh based PM structured approach. The combined TPM algorithm takes advantage of the fact that gravitational forces are linear functions of the density field. Thus one can use doma
E. M. Henley, W-Y. P. Hwang, L. S. Kisslinger
Despite measurements which date more than 20 years ago, no straightforward solution of the ratio of the parity-conserving (P-wave) to parity- violating (S-wave) decays of the hyperons has been obtained. Here we use two 2-point methods in QCD sum rules to examine the problem. We find that resonance contributions are needed to fit the data, similar to a chiral
Sergey Kovalenko, Ivan Schmidt, Jacques Soffer
We study the possibility of a large CP/T-violation in lepton pair production in the collisions of polarized protons at RHIC-BNL. We propose the single transverse spin asymmetry which quantifies the possible CP/T-violating effect in this reaction as a sensitive indicator of physics beyond the standard model(SM). We consider two examples of mechanisms beyond t
M. P. Anantram
The current carrying capacity of ballistic electrons in carbon nanotubes that are coupled to ideal contacts is analyzed. At small applied voltages, where electrons are injected only into crossing subbands, the differential conductance is $4e^2/h$. At applied voltages larger than $ΔE_{NC}/2e$ ($ΔE_{NC}$ is the energy level spacing of first non crossing subban
A. Zabrodin
For quantum integrable models with elliptic R-matrix, we construct the Baxter Q-operator in infinite-dimensional representations of the algebra of observables.
A. Arhrib, M. Capdequi Peyranere, W. Hollik, G. Moultaka
We study the associated production of charged Higgs bosons with $W$ gauge bosons in high energy $e^+ e^-$ collisions at the one loop level. We present the analytical results and give a detailed discussion for the total cross section predicted in the context of a general Two Higgs Doublet Model (THDM).
Silvano Simula
The occurrence of the Bloom-Gilman local duality in the low-order moments of the nucleon structure function is investigated for values of the squared four-momentum transfer Q**2 between ~ 0.5 and 10 (GeV/c)**2. At variance with previous analyses truncated Cornwall-Norton moments, limited to the nucleon-resonance production regions, are considered. The role p
Armin Uhlmann
For pairs, omega, rho, of density operators on a finite dimensional Hilbert space of dimension d I call k-fidelity the d - k smallest eigenvalues of | omega^1/2 rho^1/2 |. k-fidelities are jointly concave in omega, rho. This follows by representing them as infima over linear functions. For k = 0 known properties of fidelity and transition probability are rep
Yuji Igarashi, Katsumi Itoh, Hiroto So
We show that symmetries are preserved exactly along the (Wilsonian) renormalization group flow, though the IR cutoff deforms concrete forms of the transformations. For a gauge theory the cutoff dependent Ward-Takahashi identity is written as the master equation in the antifield formalism: one may read off the renormalized BRS transformation from the master e
B. A. Grishanin, V. N. Zadkov
The coherent information concept is used to analyze a variety of simple quantum systems. Coherent information was calculated for the information decay in a two-level atom in the presence of an external resonant field, for the information exchange between two coupled two-level atoms, and for the information transfer from a two-level atom to another atom and t
Correlation Functions of Multisite Interaction Spin-S models on the Bethe-like Lattices
cond-mat.stat-mechR. G. Ghulghazaryan
Multisite interaction spin-S models in an external magnetic field are studied recursively on the Bethe-like lattices. The transfer-matrix method is extended to calculate exactly the two-spin correlation functions. The exact expressions for the correlation length and magnetic susceptibility are derived for spin-1/2 models. The singularity of the correlation l
Martin Mojzis, Joachim Kambor
Reordering of the chiral perturbation series, proposed recently by Becher and Leutwyler in the framework of SU(2) baryonic ChPT, is applied to the SU(3) case. This results in improved convergence of the chiral expansion of static properties of the lowest lying baryon octet, which in most cases is quite impressive. Finite renormalization of coupling constants
Thomas Jennewein, Ulrich Achleitner, Gregor Weihs, Harald Weinfurter
We present the realization of a physical quantum random number generator based on the process of splitting a beam of photons on a beam splitter, a quantum mechanical source of true randomness. By utilizing either a beam splitter or a polarizing beam splitter, single photon detectors and high speed electronics the presented devices are capable of generating a
Thomas Jennewein, Christoph Simon, Gregor Weihs, Harald WeinfurterD
By realizing a quantum cryptography system based on polarization entangled photon pairs we establish highly secure keys, because a single photon source is approximated and the inherent randomness of quantum measurements is exploited. We implement a novel key distribution scheme using Wigner's inequality to test the security of the quantum channel, and, a
Arthur O. Pittenger, Morton H. Rubin
Necessary conditions for separability are most easily expressed in the computational basis, while sufficient conditions are most conveniently expressed in the spin basis. We use the Hadamard matrix to define the relationship between these two bases and to emphasize its interpretation as a Fourier transform. We then prove a general sufficient condition for co
K. Kowalski, J. Rembielinski
A deformation of the Fock space based on the finite difference replacement for the derivative is introduced. The deformation parameter is related to the dimension of the finite analogue of the Fock space.
V. I. Korobov
It is known that the variational methods are the most powerful tool for studying the Coulomb three-body bound state problem. However, they often suffer from loss of stability when the number of basis functions increases. This problem can be cured by applying the multiprecision package designed by D.H. Bailey. We consider the variational basis functions of th
M. Baldo, G. F. Burgio, H. -J. Schulze
In the framework of the Brueckner-Bethe-Goldstone theory, we determine a fully microscopic equation of state for asymmetric and $β$-stable nuclear matter containing $\sim$ and $\la$ hyperons. We use the Paris and the new Argonne $Av_{18}$ two-body nucleon interaction, whereas the nucleon-hyperon interaction is described by the Njimegen soft-core model. We st
One Dimensional Regularizations of the Coulomb Potential with Application to Atoms in Strong Magnetic Fields
math-phRaymond Brummelhuis, Mary Beth Ruskai, Elisabeth Werner
We consider one-dimensional regularizations of the Coulomb potential formed by taking a two-dimensional expectation of the Coulomb potential with respect to the Landau states. It is well-known that such functions arises naturally in the study of atoms in strong magnetic fields. For many-electron atoms consideration of the Pauli principle requires convex comb
A. S. Botvina, A. D. Jackson, I. N. Mishustin
We compare different analytical and numerical methods for studying the partitions of a finite system into fragments. We propose a new numerical method of exploring the partition space by generating the Markov chains of partitions based on the Metropolis algorithm. The advantages of the new method for the problems where partitions are sampled with non-trivial
Michael Kunzinger, Michael Oberguggenberger
We present an extension of the methods of classical Lie group analysis of differential equations to equations involving generalized functions (in particular: distributions). A suitable framework for such a generalization is provided by Colombeau's theory of algebras of generalized functions. We show that under some mild conditions on the differential equ
Michael Grosser, Michael Kunzinger, Roland Steinbauer, James Vickers
We present a geometric approach to defining an algebra $\hat{\mathcal G}(M)$ (the Colombeau algebra) of generalized functions on a smooth manifold $M$ containing the space ${\mathcal D}'(M)$ of distributions on $M$. Based on differential calculus in convenient vector spaces we achieve an intrinsic construction of $\hat{\mathcal G}(M)$. $\hat{\mathcal G}(
Michael Grosser
This paper gives a comprehensive analysis of algebras of Colombeau-type generalized functions in the range between the diffeomorphism-invariant quotient algebra $\mathcal{G}^d = \mathcal{E}_M/\mathcal{N}$ introduced in part I and Colombeau's original algebra $\mathcal{G}^e$. Three main results are established: First, a simple criterion describing members
Eva Farkas, Michael Grosser, Michael Kunzinger, Roland Steinbauer
We construct a diffeomorphism invariant (Colombeau-type) differential algebra canonically containing the space of distributions in the sense of L. Schwartz. Employing differential calculus in infinite dimensional (convenient) vector spaces, previous attempts in this direction are unified and completed. Several classification results are achieved and applicat
Mutsumi Saito
For a finite set A of integral vectors, Gel'fand, Kapranov and Zelevinskii defined a system of differential equations with a parameter vector as a D-module, which system is called an A-hypergeometric (or a GKZ hypergeometric) system. Classifying the parameters according to the D-isomorphism classes of their corresponding A-hypergeometric systems is one o
Igor Bandos, Jerzy Lukierski, Dmitri Sorokin
We discuss the dynamics of a superparticle in a superspace whose isometry is generated by the superalgebra OSp(1|4) or its central-charge contraction. Extra coordinates of the superspace associated with tensorial central charges are shown to describe spin degrees of freedom of the superparticle, so quantum states form an infinite tower of (half)-integer heli
Pietro Menotti, Domenico Seminara
The canonical ADM equations are solved in terms of the conformal factor in the instantaneous York gauge. A simple derivation is given for the solution of the two body problem. A geometrical characterization is given for the apparent singularities occurring in the N-body problem and it is shown how the Garnier hamiltonian system arises in the ADM treatment by
Takao Suyama
We construct the effective theory of intersecting branes and investigate the BPS monopoles in the theory. The monopoles obtained are the generalization of Nielsen-Olesen vortex. We study the properties of the solutions and interpret them as the D0-branes on the brane-intersections.
Alan Kostelecky
The formulation and some experimental implications of a general Lorentz-violating extension of the standard model are reviewed. The theory incorporates both CPT-preserving and CPT-breaking terms. It is otherwise a conventional quantum field theory, obtained under the assumption that Lorentz symmetry is spontaneously broken in an underlying model. The theory
Kenneth Lane
I discuss high mass signatures of technicolor that would be observable at a very high energy muon collider. Most intriguing is the spectrum of spin-one technihadrons, rho_T, omega_T and A_{1T}, which may extend to 100 TeV and beyond in a walking technicolor theory.
T. M. Aliev, D. A. Demir, M. Savci
The B -> K^* l^+ l^- (l = mu, tau) is analyzed in a minimally extended Standard Model in which the Wilson coefficients have new CP-odd phases. The sensitivity of the CP asymmetry and lepton polarization asymmetries to the new phases is discussed. It is found that the CP asymmetry is sensitive to the new phase in the Wilson coefficient C_7 whereas the normal